DE1720461A1 - Thermosetting resin composition and process for its preparation - Google Patents

Description

Dipl.-Ing.F.Weickmann, Dr. Ing.A-Weickmann, Dipl.-Ing.H.Weickmann Dipl-Phys. Dr. K. Fincke patent attorneys

8 MÜNCHEN 27, MÖHLSTRASSE 22, LUFNüMMEl 4l3 »21/22 1 7 2 O A 6

Case 11,754-F

THE I) OW CHEMICAL COtIPAOT, Midland, Michigan / U.S.A.

Thermosetting resin composition and process for their preparation

The invention relates to flavored thermoset Resin-adhesive mixtures, especially epoxy resins, the 0.5 to 5 parts by weight to 100 parts by weight of epoxy resin Compatible, thermoplastic, polymeric modifying agent, which consists of at least 45 wt. ^ of a polymerizing alkyl ester of acrylic acid with 1 up to 4 carbon atoms in the alkyl radical and otherwise from one or more monoethylenically unsaturated comonomers consists.

There is a need for epoxy resin compositions that eehr raach with the formation of essentially non-sticky, flexible, thermoset materials that have a

10982S / 1997

show excellent adhesion to metals, which can be re-hardened. Attempts have already been made in the direction of increasing flexibility
Curing agents such as polyamines have been used, but these have generally been found to be unsuitable for achieving a useful rate of cure. Latent curing polyalkylenepolyamine curing agents such as diethylenetriamine have also been tried for this purpose, with a useful curing rate being achieved but undesirably brittle, heat-cured materials being formed.

According to the invention, rapidly hardening, generally non-tacky epoxy resin adhesive mixtures with significantly improved flexibility are produced by
to the epoxy resin prior to its cure O ₁ 5> to 5 'parts per 100 parts of epoxy resin of a theruoplaetischen, polyueren
Iodifying agent is added, which, when added in the required quantities, can be trusted with the epoxy resin and consists of at least 45% by weight of a polymeric acrylic

ϊ
acid alkyl esters of the formula

H H 0

t I Il

H - G = G - C - OR

BATH ORIGINAL

109825/1997

I: eiue "Ik ;, l ^ rupoe with 1 bio 4 LoIiI ens toff atoms means, i-rc otherwise composed of one or more monoethylene unsaturated comonomers. Examples of particularly preferred comonomers are (a) styrene, C <~; ieti., Vli5t ;. ^r r-jl and Ilethylmethacr .. lat, v / obei these Ilononeren or Liicniuiv'en of them in a iiesantmen ^ ev \ m üj - ■■ t liieur al3 ^ Jev .. ■>, at: o ^ eii on the Jev .'icht de.3 roIy: r.erexi ..oüii'i ^ i ^ run -siuittels, vervrendet verden, and (b) ^ C2 '.: ini tr JI, _.7jr · χ; ^ thylacrylate, methacrylic acid and *: 2T.; ± £ ^; ure, -., obei aiese Ilononeren or their Ilisohun ^ en in a j, ^ r-vutmence of uioht menr as 10 ^ ew., - ?, bezorf ¹¹ :: iUJ ': iaa oevdeiit des υοΐ ;. ::: · re? -, x-iodifi ^ ift ^ unraniittels ve ^v -v; enc.et ·: eraen.

"-.i ". ..ij.er -cV ^ Hri - :: süo "rc lyniereu l.odif izi ^ runirs- ^: * - uel ej -.... <"-> :! ^ ⁴ Ch Or <iif: .'lej- : ibi "l.ität una die .iaftung ■ · '·.: ■ :: Θ.ιαίί ..iiiel .c'i 7ei".' ei.rlu] i ...-.: ii t a Vi ^ l ^ ah] ver - ^ aipaoiit: c:;: Licjic: ¹ - ^ vo ^ ynax-ie, including the 'Jol-j- : I ;;: idyluet'i7-.vte.' ni (1):; .. eic.; r .: genes phenols, (2) al .- :, 'iyaü;.; - ii Cäi i-.vten,;: v; eib; ii; u sc'ieji riienolen, {Z) , ια ^Ί ^ .- οη-

, (4) bisphen - :; len

109B7H / 1997

17204S1

O O

tt It

in which R is an alkylene -S-, -SS-, -S- or -G- group and in which R ₁ , R ₂ , R, and R-, independently of one another, denote a hydrogen, oxygen or halogen atom, and (5 ) Polyoxyalkylene glycols. Solclae epoxy resins can be combined with all common additives including spoxy hardeners such as the polyamines, dicarboxylic acid anhydrides and the catalytic hardeners such as BF, monoethylene amine and dicyandiamide.

The following examples illustrate procedures for Production of the compositions according to the invention and their usefulness as firmly adhering coatings for metals described.

example 1

In a series of experiments, 100 wt. Parts of an epoxy resin, which consists essentially of a Diglycidyl ether of 2,2-bis (4-hydroxyphenol) propane

109825/1997

BATH ORIGINAL

_ 5 -

with an epoxy equivalent weight of 186 to 192 and a viscosity of 11,000 to 14,000 cP at k: b ° C, placed in a reactor and stirred while the reactor temperature was kept ^{at about 60 0G.} To the reactor were then individually different amounts added to one of the polymeric latices which are hereinafter referred to as samples A and B (each latex contains 50 wt. $ Polymerisatfeststoffe) üie mixtures were then each heated to 90 ⁰ C and the vapor space with nitrogen flushed to remove volatiles. Residual water was removed by further heating the mixtures to 150 ° C. in vacuo. Thereafter, 6 parts of dicyandiamide and about 2 parts of silica airgel were added, and the mixture was allowed to cool to normal room temperature while being stirred at atmospheric pressure. Individual test samples, which consisted of two steel strips 0.8 mm thick, 15 cm long and 2.5 cm wide, were sandblasted at one end, coated with one of the adhesive compositions described here and put together to form a 1.3 cm overlap. Each strip was then cured ^{at 20O 0 O for 30 minutes.} The bond strength obtained for each of the individual

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Γ / 20461

Samples were measured using a commercially available tensile strength analyzer determined, determining the tensile shear force required to tear the bond became.

The samples used and the tensile shear strength determined are given in Table I below.

Sample no.

Modified, Medium

for comparison

1 none
according to the invention

2 A

Table I.

Amount of latex polymer solids (parts per
100, related to weight)

0.5
1.0
2.0

0.5
1.0

Tensile shear strength

kg / cm

200.7

260.3 342.0 305.1

299.5 327.6 308.6

A = 62.7 / 'butyl acrylate, 34.3 $ acrylonitrile and

3, O ^ methacrylic acid

B = 67 '/ ό ethyl acrylate, 33/4 methyl methacrylate, 1? » Methacrylic acid and $ 0.5 acrylic acid

109825/1997

BATH ORIGINAL,

Γ / 20461

example 2

A number of additional attempts were made, respectively individual polymeric modifiers (hereinafter referred to as Samples G through H) separate the epoxy resin from Example 1 in the form of a latex containing 50 tfew./j polymer solids contained, added in an amount of about 2.3 parts of polymer solids per 10 parts of epoxy resin.

Each mixture was then ^{heated to 90 °} C. and the combat chamber was flushed with nitrogen to remove volatile constituents, and then further ^{heated to 150 °} C. under reduced pressure (29.5 mm Hg). Then 8 parts of dicyandiamide, i? Parts of silica airgel and 70 parts of aluminum powder (all based on the weight of the epoxy resin) were added and the mixture was allowed to cool to normal room temperature while stirring at atmospheric pressure. Each composition was then tested as an adhesive coating for steel after the iiethodes tested in the ASTM test Hr. D-1002 (Lappensch ^ er test) and Kr. D-1781 (drum peel-off) are described.

Table II below lists the polymeric modifiers used and those achieved Physical properties stated.

109825/1997 ^C

S -

Tabel none according to the invention G II Tensile strength properties Drum pull-off value Sample no, polymeric modes 5 D. Lappenscher, v / ert fixing agent b E. 0.07-0.14 for comparison 7th P. 386.7 4th 8th α 0.28 9 H 469, ύ 0.48 10 416.2 1.54 492.1 0.47 483.0 0.03 385.3 0.48 408.4

C = 66yj ethyl acrylate, 1% methacrylic acid, 0.5; "° acrylic acid,

2, b ^and / or methyl methacrylate

D = bb, 6 $ butyl acrylate, 3> Methacrylic acid,!>, · ■ acrylonitrile, b & Hydrox, ethyl acrylate

E = 87/0 ethyl acrylate, 3 ^ methacrylic acid, 5y acrylonitrile, 4ϊ-3 hydroxyethyl acrylate

Ρ = 68? B butyl acrylate, 29 ^ O (-ethylstyrene, 1, 5 ^ methacrylic acid, ι, ί? ^ acrylic acid

U = 4b, 5? O butyl acrylate, 49.5 '; o ütyrol, 1: ^ netliacrylsMure, ϋ ', - i Acr ;. icrüure, 1 '; ί Hydroxy-thylacr.y lat

H = 57.5'ä butyl acrylate, 3% methacrylic acid, I / o acrylic acid, 3b, 5 / j meth, methacrylate

BAD ORiGINAL '

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1770461

Me ir; The values shown in Examples 1 and 2 illustrate the unexpected Uli tali chic it of the polymeric modifiers according to the invention to improve the ICIe beer and the flexibility of ^ poxyh / nTKen against metal. These polymeric modifiers can be used successfully in any amount described herein. In addition, the polymeric iodinizers can be added to the epoxy resin, optionally in "solution" form, using any useful chemical.

10982 S / 1997

Claims (1)

P A T ί if Ϊ A N S P Ii 'ϋ C K Ii 1. Thermosetting resin mixture, characterized in that it contains 100 parts by weight of an epoxy resin and 0.5 to 5 parts by weight. Contains parts of a thermoplastic, polymeric modifier which is compatible with the epoxy resin and of at least 45 wt .; » a polymeric acrylic snureaUcylesterfs with 1 to 4 carbon atoms in the alkyl group and im the rest of one or more monoethylenically unsaturated Comonomers consists. 2. Resin mixture according to claim 1, characterized in that the monoethylenically unsaturated Comoiioneren of the thermoplastic, polymeric modifier (a) are Jtyrene, O ^ -iethylstyrene or methyl methacrylate and the total amount of these coinonomers or their mixture is less than bO wt.? «, Based on the weight of the thermoplastic polymeric modifier, or (b) acrylonitrile, hydroxyethyl acrylate, methacrylic acid or acrylic acid, the total amount of these gomonomies or their mixtures being less than 10% by weight, based on the weight of the thermoplastic polymers FIoJlfizierun _; * ürni ttels auonacht. BATH ORIGINAL 109825/1997 Γ / 20461 '>. Process for the production of a thermosetting y.goziyiLHTzes with improved adhesion to metals, characterized in that aa.ii see to 100 parts of the epoxy resins before their hardening to the thermoset state between 0.5 and '• j file of a theraoplas ti, polymeric codification are intended to be, which is contractual with the epoxy resin and of at least 45 wt.;? of a polymerized alkyl alkyl ester with 1 to 4 carbon atoms i.:n λ1κ \ lreyt and otherwise eus one or more nonoäthyleniecii tui .; ^r esaturated coinonomers. 4. The method according to claim 3, characterized in that ¹ / the niononthylenically unsaturated gomonomers of the tuar ^ o plastic, polymeric modifying agent (a):; t;> ro2, O ^ - '^ -' t- ^ yls ^ yrol or Ilethylraethnacrylat are, the total amount of these cononomers or their 1-slings less than 50 'Jew. i based on the weight of the; ther ^ i.iorlastiscLen polymeric iiOdifzierungsmittels, susnaent, uii · -: (bj acrylonitrile, lj; ^r droxyäthylacrylat, Methaci \ '.- ^i3: iure and acrylic acid: ij: u, v; obei the äesamtir.erige this ^f: oj: i0nomers or their references less than Io Jew .. *, based on the weight of the thermoplastic, uolynous iodifirating agent. 10987 S / 1997 Γ / 20461 ^. v'eri'anreri nacu Ansvruci; '"jaer 4, thereby ^ p ..ej c: .ii.e ^, '.ta :: claa ther;:. Q-.ia2tiGCi; e, polymeric Modii'i ^ ier Ui, -ittel xtt dem Jpoxyiiar ^ in; o; .v, one rol: r.: ereri .Luxex: .ü _t : ecei..t will. 10982S / 1997 BAD OR, _QI , MAL.